The Gene Ontology Handbook

Volume 1446 of the series Methods in Molecular Biology pp 245-259

Open Access This content is freely available online to anyone, anywhere at any time.


The Evidence and Conclusion Ontology (ECO): Supporting GO Annotations

  • Marcus C. ChibucosAffiliated withDepartment of Microbiology and Immunology, Institute for Genome Sciences, University of Maryland School of Medicine Email author 
  • , Deborah A. SiegeleAffiliated withDepartment of Biology, Texas A&M University
  • , James C. HuAffiliated withDepartment of Biochemistry and Biophysics, Texas A&M University and Texas AgriLife Research
  • , Michelle GiglioAffiliated withDepartment of Medicine, Institute for Genome Sciences, University of Maryland School of Medicine


The Evidence and Conclusion Ontology (ECO) is a community resource for describing the various types of evidence that are generated during the course of a scientific study and which are typically used to support assertions made by researchers. ECO describes multiple evidence types, including evidence resulting from experimental (i.e., wet lab) techniques, evidence arising from computational methods, statements made by authors (whether or not supported by evidence), and inferences drawn by researchers curating the literature. In addition to summarizing the evidence that supports a particular assertion, ECO also offers a means to document whether a computer or a human performed the process of making the annotation. Incorporating ECO into an annotation system makes it possible to leverage the structure of the ontology such that associated data can be grouped hierarchically, users can select data associated with particular evidence types, and quality control pipelines can be optimized. Today, over 30 resources, including the Gene Ontology, use the Evidence and Conclusion Ontology to represent both evidence and how annotations are made.

Key words

Annotation Biocuration Conclusion Confidence Evidence ECO Experiment Inference Literature curation Quality control